The present invention relates to tooling devices and, more particularly, to apparatus and methods for retaining objects on a surface.
In machining, and in particular metal forging, it is desirable to fix an object to be machined to a base plate so that a machine may act on the object without moving the object. For example, in forging presses or milling stations, a base plate may be provided to allow a block of material, such as a block of metal, to be secured to the base plate so that the machine may act on the block without risk that the block will unintentionally be dislodged from the base plate. This securing is especially important in fields requiring highly precise mechanical components, such as the aerospace industry. This type of securing is also important to prevent accidental movement of the block that might injure operators of such machines.
In machine tools, such as forging presses, a base plate is provided to hold the object being machined. The base plate may have one or more T-slots extending along the surface of the base plate. The T-slots permit slidable insertion of a threaded bolt having a head. The body of the bolt extends through a portion of the object, and a nut is threadedly tightened onto the bolt. Tightening the nut and bolt causes the object to which the bolt is engaged to be secured to the surface of the base plate. Conventionally, the nut and bolt are tightened using a wrench that can rotate either the nut or the bolt so that the bolt head abuts the narrow channel of the T-slot and brings the engaged object into a secure position with respect to the surface.
Examples of various devices for retaining objects to surfaces are disclosed in U.S. Pat. Nos. 2,707,419; 3,687,443; 3,935,679; 3,936,983; 3,942,780; 4,170,345; 4,181,296; 4,477,064; 4,819,922; 4,850,255; 5,255,901; 5,535,995; 5,732,937; 5,961,107; 6,035,505; 6,039,312; 6,070,334; and 6,105,949.
The foregoing devices all may suffer from the problem that they may involve an excessive number of components, and may be relatively complicated and difficult to use. In particular, the conventional nut and bolt procedure mentioned above can take a significant amount of time, and can waste resources. Because forging metals requires high temperatures, the nuts and bolts, as well as the other components of such clamping devices, are similarly exposed to high temperatures. The high temperatures and the repeated tightening of the bolts may cause them to fatigue and/or break repeatedly.
Accordingly, there remains an unmet need for a device that may be reliably secured to a surface and that is simple and easy to use. Such a device should be useful in securely retaining objects to the surface. In forging applications, the device should withstand the extremely high temperatures, and thus should not be prone to problems that may be associated with conventional devices.
The present invention provides an apparatus and methods for retaining objects to a surface. The apparatus generally comprises a body, a lock pin, and a slide pin. The slide pin and lock pin interact so that movement of the slide pin results in movement of the lock pin so that the lock pin can secure the body to a surface. The apparatus is used as a clamp to hold an object on the surface. The apparatus may clamp the object by engaging a portion, such as a lip, extending from the object, or may clamp the object by engaging a groove of the object, or may clamp the object by pressing the object against a rigid surface, or may clamp the object by pressing the object against another clamp.
In one embodiment, an apparatus for retaining a workpiece on a surface having at least one slot comprises a clamp body having a bottom face that can be positioned on the surface; a lock pin extending from the bottom face of the body; and at least one pin extending through the clamp body and operably engaged with the lock pin so that movement of the at least one pin causes movement of the lock pin so that the lock pin lockingly engages the clamp body with the surface. The pins of the foregoing apparatus may be slidably engageable to cause the lock pin to be pulled within the surface thus fixing the apparatus to the surface. The pin may extend through a hole in the lock pin and through the clamp body
An apparatus for retaining a workpiece on a surface having at least one slot may also comprise a clamp body having a bottom face positionable on the surface; a lock pin extending from the clamp body, the lock pin having an end that engages with a slot of the surface; and at least one slide pin projecting through the clamp body and the lock pin.
The foregoing apparatuses may also comprise an engagement member for engaging the workpiece. The engagement member may be provided on the front surface of the clamp body, and may include one or more pins disposed therethrough and extending into the clamp body. Displacement of the pins may cause a displacement of the engagement member so that the engagement member provides additional retentive forces on the workpiece. The lock pin of the foregoing apparatuses may have a head engageable with a T-slot provided on the surface, and in one embodiment, it may be T-shaped. The slide pin of the foregoing apparatuses may also have an angled longitudinal surface so that the width of the slide pin changes and the slide pin may swedgingly engage the lock pin.
An impact clamp assembly for retaining a workpiece on a surface having at least one slot may comprise a clamp body positionable on the surface; a lock pin extending from the clamp body and slidably disposed therein; at least one slide pin projecting through the clamp body and the lock pin; and means for engaging the workpiece so that the workpiece is retained on the surface.
The means for engaging the workpiece of the foregoing assembly may comprise an engagement member positioned at the front surface of the clamp body, and may also comprise a plurality of slide pins extending through the engagement member into the clamp body, or the means for engaging the workpiece may comprise a support extending from the clamp body and away from the surface to which the clamp body is attached, and a brace on the support that is engageable with the workpiece. The foregoing assembly may also comprise a second clamp body having a lock pin extending therethrough and at least one slide pin extending through the clamp body and the lock pin. The two clamp bodies may act as a vise secured to the surface and to opposite sides of the workpiece.
The components of the foregoing devices may be made from heat-resistant steel.
A method for attaching an impact clamp to a surface having at least one slot, comprises the steps of: (a) providing an impact clamp having a lock pin extending from a clamp body and having an end engageable with the slot of the surface, and at least one slide pin extending through the body and the lock pin, the slide pin having an angled longitudinal surface permitting a swedged engagement of the slide pin with the lock pin; (b) positioning the impact clamp on the surface by aligning the lock pin with a slot; and (c) urging the slide pin into the lock pin and body so that the slide pin swedgingly engages with the lock pin causing the lock pin to clamp the surface between the body and the end of the lock pin.
The foregoing method may also include the step of engaging an engagement member of the impact clamp with a workpiece so that the workpiece is retained to the surface. The workpiece may be fixed to the surface by clamping the workpiece between the impact clamp and the surface, or may be wedged between the impact clamp and another surface, including another impact clamp.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art.